1. Field
Example embodiments relate to an analog level meter and a method of measuring analog signal level, and for example, to an analog level meter using duty ratio capable of detecting an analog peak/bottom level without an analog to digital converter and a method of measuring analog signal level using duty ratio capable of the same.
2. Description of Related Art
An analog level meter may include an analog to digital converter (ADC) to convert an analog signal into a digital signal. However, when a frequency of the analog signal is higher than a sampling frequency of the ADC, sampling may not be performed properly. Accordingly, it may be necessary to adjust a level of an input analog signal to improve the operation of the ADC.
FIG. 1 is an example diagram showing a conventional analog level meter with an analog to digital converter ADC.
Referring to FIG. 1, the conventional analog level meter 10 may include an offset control unit 11, a gain control unit 12, a peak/bottom detector 13 and/or an analog to digital converter ADC 14.
The offset control unit 11 and/or the gain control unit 12 may control an offset and/or a gain of the analog signal to adjust the level of the analog signal to a level at which the ADC operates properly. The peak/bottom detector 13 may detect a peak value and/or a bottom value of the analog signal of which the level may be adjusted.
FIGS. 2A and 2B are example circuit diagrams showing a conventional peak/bottom detector.
Referring to FIGS. 2A and 2B, the peak/bottom detector 13 may include an operational amplifier (op amp). The non-inverting terminal of the op amp may receive the analog signal, and the inverting terminal of the op amp may receive the output of the op amp by feedback. The peak/bottom detector 13 may detect the peak value or the bottom value by limiting a source current or a sink current of the op amp.
Referring to FIG. 1, the ADC 14 may perform analog to digital conversion with respect to the detected peak value and/or bottom value.
However, the conventional analog level meter may have to include the offset control unit and/or the gain control unit to adjust the level of the analog signal to the level at which the ADC operates properly. Accordingly, the layout area of the analog level meter may increase. The conventional analog level meter may further include capacitors, which in turn, may increase the number of elements and/or change the characteristics of the capacitors according to processes.